Moon by Simaudio 888 monoblock power amplifier

Not everyone needs a power amplifier that can deliver 888W RMS into 8 ohms or 1776W into 4 ohms. You could say that no one needs one of these—or two, if you want to listen in stereo. Most household AC systems can't even provide enough current to deliver all that power. But Simaudio does build Moon 888 monoblocks, and people do buy them, whether or not they need an amp that weighs about 250 lb each and costs $118,888/pair.

But forget about need. Would you want a pair of these massively heavy amps? People into tubed gear might not, but if price was not a consideration and if you had the room, chances are good that the rest of you would. After listening to a pair in my listening room, I did.

Some months ago, Costa Koulisakis, Vice President–Customer Experience and part owner of Simaudio Ltd., rolled two Moon 888s into my ground-level listening room and, with great difficulty, lifted each off its dolly and plopped both down on my carpeted cement floor. While setting a powerful audio amplifier directly atop carpet is not usually advised, Koulisakis assured me that it would be safe. Each amp's four big, spring-loaded, self-leveling feet rose to the occasion.

When the Moon 888s were in place, Koulisakis removed the top panel of one of them and gave me a tour. I shot a video of it.

Inside and Out
The Moon 888 is big—22" wide by 14" high by 27" deep—and its construction quality is heroic. It's so sturdily built that I could safely stand atop one to replace a ceiling lightbulb. (Don't tell anyone at Simaudio I did that.) The large, extremely heavy top panel is made of cast aluminum, its underside ribbed for extra pleasure—I mean, extra strength—and covered in a vibration-deadening paint.

The cleanly laid-out rear panel offers two sets of easily accessed speaker terminals for biwiring. Below these are single-ended (RCA) and balanced (XLR) inputs (I ran balanced exclusively), a switch for choosing between them, and another switch for selecting AC or DC coupling (see below). Below those are an RS-232 port for automation and updates, a 12V trigger input and output, a 20A IEC power inlet, a fuse, the main power rocker switch, and three warning lights, labeled Thermal, DC Level, and Other.

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Each side panel is actually a single large heatsink comprising not a series of bolted-together sections but a single aluminum casting. Simaudio claims that this dissipates heat more evenly, to ensure that all 32 bipolar transistors in this fully balanced, dual-differential amp consistently run at the same temperature. This casting includes a series of channels and indentations designed to control vibrations. Every other part of the case and chassis is machined from aluminum.

If you watch my video you'll see that high-quality parts are used throughout the 888. The two large, custom-wound transformers have been potted inside large chromed cylinders. The 12 big, custom-made power-supply capacitors in the main storage bank have a total capacity of 324,000µF, augmented by secondary and tertiary storage caps, including one next to the output transistors, for a total of just over 400,000µF—not surprising in an amplifier claimed to double its already impressive specified output each time the impedance is halved.

The Moon 888 can be AC- or DC-coupled via a switch on its rear panel. Simaudio says that DC coupling produces less phase distortion and thus better bass resolution. However, despite the 888's sensitive DC-detection circuitry and proprietary DC servo, any amount of DC amplified to full power by the 888 would spell certain doom for any speaker hooked up to it. So while Simaudio recommends setting this switch to DC when using a Moon preamplifier, they urge caution when using preamps made by other brands, when AC coupling should be used. I ran the 888s DC-coupled without incident, first using a darTZeel NHB-18NS preamplifier, then a CH Precision L1.

Simaudio themselves make every major part of this amplifier, other than the two pairs of large, clutched, rhodium speaker terminals, which are made in Japan by Furutech. When the speaker cable has been sufficiently tightened, the clutch slips, to ensure a secure fit and prevent you from overtightening the connection and possibly even breaking something.

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According to Costa Koulisakis, when a Moon 888's subassemblies have been finished, the amp is then hand-assembled by a team that then does nothing else until that amp is finished. He told me that it takes about a week to assemble one 888.

Simaudio sent me a white paper explaining the origins of the Moon 888. Evidently the model had been "brewing" in the engineering quarters for at least a decade, but "reality" and "marketing pressures" dictated that Simaudio first develop more affordable products. Over the past three years, however, Simaudio claims it has seen products "emerge in the marketplace with exorbitant price tags," many from unknown "start-ups" whose futures are equally unknown. Meanwhile, throughout the past decade, all of the costliest and "tweaky-ist" sound-improving ideas Simaudio has been unable to implement in its more affordable products were thrown into what it calls its "skunkworks closet," in the hope that someday that closet could be emptied and the ideas therein put to good use.

Ultimately, while many if not most of the skunkworks ideas went into the design of the Moon 888, Simaudio chose a generally conservative route, including eschewing a new look in favor of something that would better match the company's other products. Rather than use a new and "revolutionary" circuit design, the company stuck with its proven amplifier technology, but greatly augmented it with reference-quality, no-expense-spared parts.

Their idea seems to be: If you like the Moon 330A stereo power amp, you'll probably love the stereo Moon 860A—and if you love that, you'll really love the Moon 880M monoblock. And if you really love that, more likely than not you'll want to toss the Moon 888 in your bed and sleep with it before installing it (footnote 1).

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Simaudio admits that the Moon 888's model number—and, I guess, its price per pair of $118,888—is pure marketing: In Asia, the number 8 represents good fortune. In fact, the amp can supposedly output 888W RMS into 8 ohms. The 888's core circuit technology is taken directly from Simaudio's Moon 880M monoblock, which sells for $45,000/pair, but with "cost is no object" parts and implementation. Circuit features include zero global feedback, and only local feedback stages. Simaudio claims that they've been continuously refining their use of zero global feedback since 1986. They say it results in superbly stable amplifiers and, perhaps of equal or more importance, when properly implemented it offers superior phase characteristics and top-end clarity, which in turn result in bigger soundstages with more ambience, and more air around instruments and voices.

Another of the Moon 888's novel features, also from the skunkworks closet, is referred to by Simaudio as a "harmonized electro-mechanical output": The cast-aluminum heatsink is designed so that the output section is fully inset within it rather than being bolted on to the heatsink's outer surface. This results in the most efficient conduction of heat, aided by a large thermal pad between the output board and heatsink that draws heat away from all circuit-board components. The results, per Simaudio, are lower and more stable operating temperatures, and thus improved linearity and less distortion due to heat, which all adds up to higher sound quality.



Footnote 1: If you think that's far-fetched, back in the 1960s I knew a guy so in love with his Corvette that, after it was totaled, he slept with its engine. Name and occupation available on request.
COMPANY INFO
Simaudio Ltd.
US: Simaudio Ltd.
2002 Ridge Road
Champlain, NY 12919
(450) 449-2212
ARTICLE CONTENTS

COMMENTS
Bogolu Haranath's picture

Why so "Heavy"? ........... Linkin Park :-) ..........

Ortofan's picture

... "could pump a couple of thousand watts into the Aida — a speaker that in my room needs, on average, probably less than 20W!"

Over on the Harbeth forum, Alan Shaw posted an example of a music piece that exhibited a dynamic range of about 22dB. In that case, even if your speakers required an average power of only 20W, you'd still need an amp capable of an output of about 3,200W to reproduce the instantaneous +22dB high peaks without clipping.

Does that mean you need an amp that can output 1, 2, or 3kW continuously and, as a result, costs $100K and weighs several hundred pounds? Not at all.

Simaudio should have the skunkworks engineers take a look at the old Hitachi class G amps and then design a new amp which can output maybe 100W-200W continuously and possibly 500W-1kW for some fraction of a second - and one that wouldn't need to cost a fortune and weigh a proverbial ton.

hifiluver's picture

Sensitivity of Harbeth SHL5's are 86dB/1W/1m, 20W would produce a scary 99dB at 1m . Not sure how the journalist came to the figure of 20W. If you need 22dB headroom peaks off a base of 1W which is already very loud, you'll need an amp clean to 160W. Most decent amps rated 100W continuous should be able to meet this.

Anton's picture

You are spot on.

Ortofan's picture

... live music - even when using unamplified acoustic instruments. The key is peak - not continuous.

Watch this video of a Harbeth Monitor 40 demo:
https://www.youtube.com/watch?v=bRMR9JZ1m0s

The peak power shown on the amplifier's display is close to 800W, which means that the peak output from the speakers is about 115dB SPL. No one in the room seems to be distressed by those sound levels.

The demo track being played is this one:
https://www.youtube.com/watch?v=XhuJxdaU87I

hifiluver's picture

Yes and yes. And you're absolutely right.

Can Mr. Shaw's walking to the back of the room at position 5:08 on the video be taken as distress? How far from the speaker do you estimate he was finally standing and how many dB do you estimate that to be, as opposed to where he was standing initially?

Ortofan's picture

... was too loud for Mr. Shaw, note that they were evaluating the first samples of the latest version of the Monitor 40 speaker. Perhaps he just wanted to determine how the speakers sounded from farther back in the room. In any event, no one there has their fingers in their ears or seems to be rushing to turn down the volume control.

hifiluver's picture

'..'

hifiluver's picture

'...no one there has their fingers in their ears or seems to be rushing to turn down the volume control.'

… which is a big credit to the speakers and the electronics. But how many people listen to music like this, hours on end, in a room this big, a distance from the speakers at what still could be 99 to 100dB? Yes it proves a point, thank you gentlemen, but in doing so lost some pragmatic credibility in my estimation. I’m surprised Mr. Shaw would actually post this video because I think it’s insincere, especially when he says Harbeths are nearfield monitors.

A Ferrari can flex its muscles in certain conditions e.g. on a racetrack. A Ferrari will also work on a normal road but it won’t be (and shouldn’t be) using its full capabilities when a Toyota Camry will do the job.

Ortofan's picture

... from the CES in 2015, also with CH Precision amps.
As noted in the comments, there is one peak power reading of over 1700W and another of almost 1200W.
https://www.youtube.com/watch?v=UP8i8F62OlM

Bogolu Haranath's picture

So, is 24 Bit recording and playback better than 16 Bits? :-) ...........

Bogolu Haranath's picture

Google search says, maximum sound pressure levels of classical music played by an orchestra in a concert hall is 98 db :-) ...........

Bogolu Haranath's picture

Unless we are recording 1812 cannons .......... Loudest cannon according to Google 120 db :-) ..........

hifiluver's picture

Lets jog our memory on Newtons 2nd law. Can a domestic loudspeaker reproduce the sound of a cannon? or is what we hear on Kunzel's 1812 a scaled version for our living rooms?

Bogolu Haranath's picture

Which begs the question ......... How many of us are willing, able and prepared for listening to the sound of firing cannons in our listening rooms? ........... Please raise your hands :-) ...........

hifiluver's picture

...and before the five-oh starts showing up in our street.

Anton's picture

1812 cannons?

Come on. I want accurate reproduction of that jet engine on "Back in the USSR" at 120 - 140 dB.

I wanna experience the sensation of a Sperm Whale echolocating right there in front on me. (Gotta be careful when you read that word, you know...;-D...) 174 dB.

We are audiophiles, we need to dedicate ourselves to accurate recreation of the live event!

Bogolu Haranath's picture

According to Google ......... Blue Whales are the loudest on the planet, 188 db ........... Howler Monkey, a land animal is second loudest, 140 db .......... And yes, Blue Whales can sing :-) ..........

Bogolu Haranath's picture

According to Google ........... Tiger Pistol Shrimp is the loudest 200 db ........ It lives under sea .......... Blue Whale 2nd loudest 188 db .......... Yes, blue whales can sing :-) ...........

Bogolu Haranath's picture

These instruments can get loud ........... Trumpet 110 db, clarinet 114 db, trombone 115 db ...........

Bogolu Haranath's picture

Transmission line speakers use somewhat similar principle for bass frequencies .........

Bogolu Haranath's picture

Bose "wave guide" technology is somewhat similar ..............

Bogolu Haranath's picture

According to Wikipedia, the "perceived" dynamic range of 16 bit audio can be 120 db or more with noise-shaped dither ............

Bogolu Haranath's picture

The report you are referring to is from 1982 ......... I don't know whether that matters or not .......... The information I got is from Google ......... I don't know whether that info is current or not ........ You can check Google if you are interested .........

John Atkinson's picture
Bogolu Haranath wrote:
Google search says, maximum sound pressure levels of classical music played by an orchestra in a concert hall is 98 db :-)

That's an average or RMS level, which is not relevant to amplifier clipping. What matters is the peak value. In the early 1980s I designed and built a true peak-reading SPL meter for an article published in Hi-Fi News magazine. IIRC, the highest peak I measured with that meter at a classical orchestral concert from a mid-hall seat was 108dB (unweighted).

John Atkinson
Editor, Stereophile

Herb Reichert's picture

from that Alan Shaw video is a SPL meter (I have two in my iPhone) - why not show the viewer those 22dBs in action? I want to SEE that 115dB SPL. and a volt-amp meter accross the amplifier's output terminals!

Ortofan's picture

... a speaker sensitivity of 86dB/1W/1m should result in a peak SPL of about 115dB (for each speaker).

CH Precision claim that their amp is equipped with a "DSP that monitors the instantaneous output voltage and current" and that "both values are sampled at around 100 kHz, ensuring peak values are properly detected." If you doubt the accuracy of the power readings, ask Cossy or Heeb for the specifics of their power monitoring circuit and display.

Regarding the sound level meter on your iPhone, you should verify the response time of the meter. Most inexpensive SPL meters have a relatively slow response time and won't be able to capture instantaneous peaks with a duration in the millisecond range. Also, the meter must have a peak hold function in order to allow you to read those peak levels. Typically, this sort of performance is only available from professional instruments, such as those from B&K.

Bogolu Haranath's picture

Google search says, for a 86 db sensitive speaker we need 1024 watts to produce 116 db SPL ......... The same watts can produce 120 db SPL from a 90 db sensitive speaker .............

hifiluver's picture

Someone still has to sit no more than 1 meter away from the speakers to appreciate each and every one of those decibels.

hifiluver's picture

The Dutch gentlemen mentioned the amps are bridged. If the measurement is not compensating for this, we might be seeing twice the Watts being indicated on the meters.

Bogolu Haranath's picture

I remember several years ago one of the audio reviewers did some welding with one of the class A amps from Mark Levinson ......... JA may know about this ........ Wonder whether these Sim Audio amps can do welding? :-) ..........

Bogolu Haranath's picture

I think the audio reviewer was David Clark and the amps were ML No: 20 :-) ...........

Bogolu Haranath's picture

Ok ...... Surprisingly this info is available on Google ........... I checked it after I posted the above comments ........... It is true ...... The reviewer was David Clark and the amps were ML No.20 .......... What is even more surprising is that those class A amps were only lukewarm to touch even after the welding ....... Google even has the picture of the welded steel on the website :-) ...........

ppgr's picture

"Footnote 1: I was using the Moon 888s when I measured the spatially averaged frequency responses of the EgglestonWorks Viginti speakers that Michael reviewed in June, and one of the amplifiers went into protection a couple of times then." An 800 watts amplifier going into protection several times while driving a pair of speakers??? Either the speakers - or the amplifiers - are not optimally engineered fro real life, or am I missing something?

John Atkinson's picture
ppgr wrote:
"I was using the Moon 888s when I measured the spatially averaged frequency responses of the EgglestonWorks Viginti speakers that Michael reviewed in June, and one of the amplifiers went into protection a couple of times then."

I didn't have time to investigate further, I am afraid.

John Atkinson
Editor, Stereophile

Bogolu Haranath's picture

"Muscles" ............. Diana Ross :-) ...........

Charles E Flynn's picture

I have seen so far only bits and pieces of this new eight-part series from HBO, but in every scene in which it appears that I have seen, the director and cinematographer have made the stereo system unusually intriguing, even when it appears in the background, out-of-focus:

http://www.vulture.com/article/sharp-objects-home-stereo-system.html

John Atkinson's picture
Simaudio electronics and Dynaudio speakers.

John Atkinson
Editor, Stereophile

Bogolu Haranath's picture

It appears that the amps are not 888s ............. If they were, the whole cabinet would have come crashing down with 600 pounds of weight :-) ............

Bogolu Haranath's picture

Simaudio thanks you for all the support they are getting on this forum :-) .............

ToeJam's picture

They certainly are nice looking.

Indydan's picture

If Stereophile could get a review sample of the Naim Statement system, a review and comparison to the Moon 888 would be great!

I had the chance to hear the Naim Statement with Sonus Faber Aida's. That is an experience I will never forget!

Bogolu Haranath's picture

Bryston has an amp 28-B mono-blocks, which they say can put out 1000 watts into 8 Ohms ............ May be Stereophile could review them? :-) .............

Bogolu Haranath's picture

May be PS audio could make 1000 watt class-D mono-blocks? :-) .............

dumbo's picture

@JA

Question about this statement which I see on occasion for various Amp measurement tests:

"but it's fair to note that I didn't hold the wall voltage constant for this test"

How does one go about holding the wall voltage constant in a domestic living environment?

Thanks

John Atkinson's picture
dumbo wrote:
How does one go about holding the wall voltage constant in a domestic living environment?

Short answer: you can't, hence my measurements reflect an amplifier's output power under real-world conditions.

Longer answer: with an amplifier with unregulated power supply (almost all of them), if the wall voltage drops as the amplifier's demand for current increases, it will clip at a lower power than if the wall voltage was held constant. Manufacturers therefore specify the maximum power with a constant wall voltage.

John Atkinson
Editor, Stereophile

Ortofan's picture

... variac or a power conditioner enable manual or automatic compensation for changes in AC line voltage?

https://www.variac.com/staco_3PN10_20.htm

https://www.tripplite.com/2400w-120v-power-conditioner-automatic-voltage...

Bogolu Haranath's picture

Both Variac and Tripp-lite have several negative reviews on Amazon ........ Like, smoke coming out, plastic burning etc. ..............

John Atkinson's picture
Ortofan wrote:
Wouldn't either a variac or a power conditioner enable manual or automatic compensation for changes in AC line voltage?

It would, though a Variac large enough to maintain a constant AC voltage with this Moon amplifier would be enormous. I do have a smaller Variac, but I decided years ago that our measurements of output power would reflect what our readers would experience, not what an amplifier would deliver under perfect conditions.

John Atkinson
Editor, Stereophile

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